A micro-duct is a small conduit used for the installation of fiber optic cables In general. They have a size ranging from typically 3 to 16 mm and are installed as bundles in larger ducts. Micro-duct are typically of small diameter, flexible, or semi-flexible ducts designed to provide clean, continuous, low friction paths for placing optical cables that have relatively low pulling tension limits. Micro-duct is stored and sold on reels. Thus, most often there are unused remnants of micro-duct which cannot be used as they are not of a sufficient length. Whereby, this is most wasteful and not cost effective. Therefore, there is a need to provide a suitable coupling that is functional for interconnecting remnants of micro-duct. Currently there are no suitable couplings available to resolve this problem.
Various types of couplings have been conceived and utilized for numerous purposes. The related prior art includes U.S. Pat. No. 5,947,532 issued to Lorenz shows prior art of a “stab” type coupling. The conduit ends are inserted (“stabbed”) into a structure that contains a flexible collet. The collet is supported by an inclined surface in the structure in such a way as to permit insertion of the conduit into the structure, but prevents retraction. No tools are required for installation. However, after the conduit is inserted, it must be retracted some finite distance in order to activate the bite of the collet into the conduit. This is an obstacle in certain installations. Further, this coupling cannot be removed from the conduit without destroying the coupling or damaging the conduit.
Further examples of related prior art include U.S. Pat. No. 7,125,056 issued to Saarem, U.S. Pat. No. 2,913,262 issued to De Cenzo et al, U.S. Pat. No. 4,008,937 issued to Filippi, U.S. Pat. No. 4,346,428 issued to Gale, and U.S. Pat. No. 5,380,052 issued to Hendrickson all of which are couplings that utilize a toggle clamp to couple conduits. All of these examples require preparing the conduit ends with beads, threaded adaptors, grooves and the like. Therefore, the noted techniques would not be desirable or accepted in the field of the present invention.
The noted prior art couplings are suitable for their intended use. However, none are functional for interconnecting micro-duct remnants as each are much too large and more importantly due to their shape they cannot be easily pulled through a conduit as they each have protruding components which tend to become snagged. Also, being micro-ducts are bundled side-by-side there is limited space there between. Therefore, the noted couplings cannot be utilized as there is not enough space for the coupling between each micro-duct when bundled. Still further, prior art couplings include internal gripping teeth which can damage the micro-duct. Also, once installed they are difficult to remove and are not re-usable.
Therefore, there is a great need for a micro-duct reclamation coupling that is sleek, small, of simple construction and most importantly free from any protruding components.